Blastema-independent Mechanism for Regeneration in Salamanders

蝾螈的不依赖胚基的再生机制

• 批准号: 10553618
• 负责人: David M. Gardiner
• 金额: $ 17.27万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10553618
• 关键词: Adult; Ambystoma; Ambystoma mexicanum; Amphibia; BMP7 gene; Biological Assay; Biological Models; Biology; Bone Morphogenetic Proteins; Candidate Disease Gene; Cells; Data; Dermal; Dermis; Enzymes; Epidermis; Epigenetic Process; Event; Failure; Fibroblasts; Future; Gene Expression; Gene Expression Profiling; Genes; Genetic; Gland; Goals; HDAC10 gene; Hair follicle structure; Histologic; Histone Deacetylase; Human; Image; Injury; Knowledge; Learning; Ligands; Limb structure; Macrophage; Mammals; Mediating; Mesenchymal; Microscopy; Modeling; Molecular; Molecular Profiling; Multipotent Stem Cells; Natural regeneration; Nerve; Pathway interactions; Population; Process; Proteins; Repression; Role; Salamander; Shoulder; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Skin; Study models; Sweat Glands; Testing; Thick; Time; Tissue Recombination; Tissues; Transcription Repressor; Translating; Work; Wound models; antagonist; appendage; blastema; candidate identification; cell type; confocal imaging; differential expression; gene repression; healing; innovation; insight; novel; organ repair; prevent; progenitor; regenerative; single-cell RNA sequencing; skin regeneration; skin wound; tissue regeneration; transcription factor; transcriptome sequencing; wound; wound healing

PROJECT SUMMARY While human and other mammals are limited in their abilities to regenerate, the salamanders, including Ambystoma mexicanum (axolotl) are highly regenerative and have provided numerous insights into the mechanisms of organ repair. Upon injury, axolotls generate “blastema” tissue at the wound site, which harbors multipotent progenitors that engage in regenerative healing, contributing to multiple newly forming cell types. The inability of mammals to form multipotent blastema cells is commonly thought to be the key barrier to true regenerative wound healing. Axolotls can also regenerate skin, which normally consists of an epidermis, a two- layer dermis as well as many secretory glands. Contrary to the prevailing notion that complete tissue regeneration requires blastema, we now show that the axolotl skin regenerates without a blastema and that, in fact, blastema formation represses glandular skin regeneration. This application will focus on defining a novel cellular and signaling mechanism of blastema-independent skin regeneration in salamanders. To achieve this goal, this project will leverage the analytical strengths of the so-called Accessory Limb Model (ALM) – a highly tractable wound model system in axolotls that can be experimentally directed to either: (i) rapidly regenerate gland-containing skin without a blastema, or (ii) form a blastema when presented with a deviated nerve and display prominently delayed skin regeneration. Using a combination of live axolotl imaging, lineage tracing, single-cell RNA-seq, functional protein delivery, and gene perturbation assays in the ALM model, in our first aim we will establish if amphibian skin gland regeneration critically depends on epidermal-dermal interactions and if these interactions are prevented in blastema-forming wounds due to the immaturity of their fibroblasts. The second aim is to uncover new signaling and epigenetic mechanisms of gland neogenesis in regenerating skin. In particular, we will establish the activating role of the Bone Morphogenic Protein ligand BMP7 and the counterbalancing role of its antagonist GREMLIN and the activating role of Class II histone deacetylase HDAC10 – top-listed differentially expressed genes in our RNA- seq studies – on gland regeneration and skin fibroblast lineage maturation. The study premise is strong, based on substantial preliminary data. The proposed studies are significant because they will introduce amphibian skin as a novel model for studying mechanisms of skin regeneration and will advance knowledge on skin cell types in amphibians. The proposed studies are innovative because they will establish a novel paradigm of blastema-independent regeneration and will identify new skin regeneration-inducing epigenetic and signaling factors. Ultimately, we want to be able to translate new knowledge learned from this amphibian model system of blastema-independent skin regeneration to better understand skin regeneration mechanisms in mammals, whose tissues typically heal without a blastema.

项目摘要 尽管人类和其他哺乳动物的再生能力受到限制，但包括 Ambystoma Mexicanum（Axolotl）具有高度再生性，并提供了许多见解 器官修复机理。受伤后，axolotls在伤口部位产生“ Blastema”组织 从事再生愈合的多能祖细胞，有助于多种新形成的细胞类型。 哺乳动物无法形成多能渗透细胞的能力通常被认为是真实的关键障碍 再生伤口愈合。 Axolotls还可以再生皮肤，通常由表皮组成 层真皮以及许多秘密腺体。与完整的组织相反 再生需要Blastema，我们现在证明Axolotl皮肤无需刺激性就可以再生 事实，Blastema形成腺皮肤再生。 该应用将着重于定义非独立的细胞和信号传导机制 萨拉曼的皮肤再生。为了实现这一目标，该项目将利用 所谓的附件肢体模型（ALM） - 可以是高度易处理的伤口模型系统 实验指向任何一个：（i）迅速再生无胚芽的皮肤，或（ii）形成A Blastema当出现偏离神经并显示出突出延迟的皮肤再生时。使用 活轴突成像，谱系跟踪，单细胞RNA-seq，功能蛋白递送和基因的组合 ALM模型中的扰动Assas，在我们的第一个目标中，我们将确定两栖 至关重要的是表皮 - 德法相互作用，如果在胚泡形成中阻止了这些相互作用 第二个目的是发现新的信号和表观遗传 腺体新生成的机制在再生皮肤中。特别是，我们将确定 骨形态形态蛋白配体BMP7及其拮抗剂Gremlin的平衡作用 II类Hisstone脱乙酰基酶HDAC10的激活作用 - 在我们的RNA中列出了不同表达的基因 SEQ研究 - 关于腺体再生和皮肤成纤维细胞谱系成熟。 基于大量初步数据，研究前提很强。拟议的研究是 意义重大，因为它们会引入两栖动物作为研究皮肤机制的新型模型 再生并将提高有关两栖动物皮肤细胞类型的知识。拟议的研究是创新的 因为他们将建立一个新颖的玻璃体独立再生范式，并将识别新皮肤 再生引起的表观遗传和信号传导因子。最终，我们希望能够翻译新的 从这种独立于胚胎的皮肤再生的两栖动物模型系统中学到的知识 了解哺乳动物的皮肤再生机制，其组织通常在没有胚芽的情况下愈合。